Among the many important issues that will be shaped by the midterms is special counsel Robert Mueller’s investigation into Russian interference in the 2016 presidential election. While any number of things could happen depending on the outcome, let’s look at the most likely consequences of a Democratic or Republican victory.

If Democrats achieve the net gain of 23 seats they need to win the House of Representatives, we can expect a bevy of aggressive oversight maneuvers. First would likely be an attempt to advance legislation protecting Mueller from firing by Trump or whoever is leading the Justice Department. The Republican-controlled Senate has already shown some willingness to take up similar legislation. Earlier this year, Senate Republicans moved a bill forward that would have protected Mueller, despite the objections of Senate Majority Leader Mitch McConnell. This effort may also include attempts to shape the way Mueller’s final report is released. Right now, Mueller reports to Deputy Attorney General Rod Rosenstein, who will receive the special counsel’s report and can decide to make it public, share it with Congress, or both.

This will just be the start of Democrats’ efforts to make up for two years of marginal congressional actions regarding the Trump administration’s ties to Russia. If the Dems take the House, we should also expect plenty of investigations and requests for testimony regarding Trump’s Russia ties. Rep. Adam Schiff, who would likely take over the House Intelligence Committee in the event of a Democratic victory, has vowed to investigate everything from Trump associates’ communications with Russians during the 2016 campaign to whether Trump is laundering money for Russian criminal interests. However, expect these investigations to move carefully. If Democrats become too zealous, they could harm Mueller’s investigation by offering immunity in exchange for testimony from key witnesses.

Meanwhile, House Judiciary Committee lawmakers could move forward with plans to impeach Trump. Democrats would need the Senate to move impeachment proceedings forward, something that’s extraordinarily unlikely to happen under any scenario. The impeachment option, as Jack Goldsmith wrote in the Weekly Standard, would also come with the risk of Trump going nuclear with a flurry of “pardons, dismissals of executive officials, and security clearance revocations” in an attempt to slow any federal investigation into his ties with Russia and possible crimes. (If Trump went that route, lawmakers could respond by initiating an independent commission to explore Trump’s connections with Russia.)

And if Republicans hold the House? We can expect the same level of oversight—that is, little to none—that we’ve seen from Congress for the past two years. A major concern for anyone supporting Mueller’s investigation is that Trump will attempt to remove Rosenstein from office in an effort to squelch the investigation. While Trump can remove Rosenstein regardless of which party comes out on top tonight, a Republican-controlled House would allow him to do so with less fear of pushback from Capitol Hill. If Trump removes Rosenstein, reports indicate he will seek to replace him in an acting capacity with Attorney General Jeff Sessions’ chief of staff Matt Whitaker, a man described as “the West Wing’s ‘eyes and ears’ in a department the president has long considered at war with him.” However, because Whitaker would only be acting as the deputy attorney general, he wouldn’t supervise Mueller. That task would likely go, at least temporarily, to current Solicitor General Noel Francisco, although he may have to recuse himself thanks to the fact that his former law firm, Jones Day, represented the Trump campaign. Whoever ends up supervising Mueller in the event Rosenstein departs can do plenty to blunt the special counsel’s investigation, including deciding when investigatory actions are “inappropriate or unwarranted under established Departmental practices” or choosing to keep Mueller’s report under wraps.

Even if Trump decides he doesn’t want to risk the political blowback that would result from ousting Rosenstein, he might still attempt to prevent Mueller’s report from seeing the light of day, either by deeming the document classified or by attempting to invoke executive privilege, the latter of which would almost certainly be contested. Again, he could attempt to do this regardless of which party controls Congress, but given its track record over the past two years, a Republican House seems unlikely to push back on any efforts by Trump to bury Mueller’s findings.